Wireless Sensor Networks Security Lindsey McGrath and Christine Weiss

Agenda Introduction Background - Problem Statement Requirements for Sensor Network Security Attacks on Sensor Networks Security Services Challenges Conclusion

Introduction What is a Sensor Network ? –A heterogeneous system combining tiny sensors and actuators with general-purpose computing elements. Most consisting of hundreds or thousands of low-power, low-cost nodes deployed to monitor and affect the environment. What are they used for? –Ocean and wildlife monitoring. –Monitoring of manufactured machinery. –Building safety. –Earthquake monitoring. –Variety of military applications. –Medical monitoring and research. Addressing Sensor Network Security…existing security mechanisms are inadequate! What are the security issues? What security services will work?

Background-Problem Statement Network Assumptions –Insecure links – non denial of eavesdropping. –Replay and injection of packets. –Non tamper resistant. Trust Requirements –Base station and aggregation point trustworthiness. Threat Models –Outsider vs. insider attacks. –Mote-class vs. laptop-class attackers. Security Goals –Integrity, authentication, freshness and confidentiality.

Requirements for WSN Security Data Confidentiality – omission of data leaks to neighboring networks. Data Authentication – verification of sender/receiver. Data Integrity – non altered transmission of data. Data Freshness – ensuring data is recent while allowing for delay estimation.

Attacks on WSN Spoofed, altered and replayed routing information Selective Forwarding Sinkhole attacks The Sybil attack Wormholes

Security Services Link-layer encryption and authentication Multi-path routing Identity verification Bidirectional link verification Authenticated broadcasts

Challenges The existing infrastructure is already resource-starved. –Communication bandwidth –Power –Computational power Preventing insider attacks. Sinkhole attacks and wormholes – no known countermeasures to apply after the protocol is designed. Building multi-hop routing topology - Nodes within one or two hops of the base station are attractive to intruders.

Conclusion Currently proposed routing protocols for WSNs are insecure but vital. Link layer encryption and authentication mechanisms provide reasonable defense for mote-class outsider attacks. Cryptography is inefficient in preventing against laptop-class and insider attacks. Remains an open problem for additional research and development.

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